Most central banks utilise an inflation target, where their primary objective is to deliver low and stable inflation. And this is how we typically judge whether they are doing their job. For example,
However, many economists question whether this is the best way to conduct monetary policy. Instead of trying to keep consumer prices stable and assume that other important variables will follow from that, an NGDP target aims for a stable environment for all wage and debt contracts, because labour and credit markets are more important for economic planning than a specific set of consumer prices. Indeed, NGDP is less volatile than CPI, and NGDP is more relevant for concerns about debt sustainability.
It is therefore interesting to see that even back in 2012 NGDP targets were receiving attention from important central bankers: